Reliance ADA Group Chairman Anil Ambani's failure to conclusively recall details about his group companies and their financial transactions prompted the Delhi court, trying the 2G spectrum allocation case, to advice him to remember something.

Asked a question by CBI related to alleged associate company of Reliance ADAG, 54-year-old Ambani said he was unable to recall if it was a part of his group company.

To this, the court advised him that such answers can also go against him.

"You must be knowing the name of promoter of the companies. This is just an advice for you. It can go against you also that you even don't know the names of your companies. So be careful," the court said when Ambani told him that there was a large number of firms in his group and he does not recall.

During his deposition, when Ambani told the court that he was not able to recall most of the answers, the judge told him that he was "under obligation to tell the truth to the court" and he was turning "hostile".

"Gawah to hostile hai kuch nahi keh raha (witness is hostile, he is not saying anything)," the court remarked.

The judge, who called Ambani an "impressive and important person", said everybody, including lawyers, was trying to "impress" him.

"Everybody is trying to impress the witness. Please speak a little less. He is a big man," the court said when defence counsel were raising objections to lot of questions asked by CBI to Ambani.

During the hearing, the court asked the CBI prosecutor to confine himself to Ambani's statement recorded earlier section 161 (examination before police officer) of CrPC and also the agency's prayer in which it had mentioned the points on which it wanted to examine him.

"Try to confine yourself to witness' 161 CrPC statement and your prayer. I was also under the impression that you will ask questions related to your prayer only," the court said.